diff --git a/src/Symfony/Component/DependencyInjection/Dumper/PhpDumper.php b/src/Symfony/Component/DependencyInjection/Dumper/PhpDumper.php
index dd1581dc040e..1a694a8d099b 100644
--- a/src/Symfony/Component/DependencyInjection/Dumper/PhpDumper.php
+++ b/src/Symfony/Component/DependencyInjection/Dumper/PhpDumper.php
@@ -1030,12 +1030,13 @@ private function startClass(string $class, string $baseClass, string $baseClassW
 use Symfony\Component\DependencyInjection\Exception\LogicException;
 use Symfony\Component\DependencyInjection\Exception\RuntimeException;
 use Symfony\Component\DependencyInjection\ParameterBag\FrozenParameterBag;
+use Symfony\Component\DependencyInjection\ParameterBag\ParameterBagInterface;
 
 /*{$this->docStar}
  * This class has been auto-generated
  * by the Symfony Dependency Injection Component.
  *
- * @final since Symfony 3.3
+ * @final
  */
 class $class extends $baseClass
 {
@@ -1088,12 +1089,12 @@ public function __construct()
         $code .= <<<EOF
     }
 
-    public function compile()
+    public function compile(): void
     {
         throw new LogicException('You cannot compile a dumped container that was already compiled.');
     }
 
-    public function isCompiled()
+    public function isCompiled(): bool
     {
         return true;
     }
@@ -1184,7 +1185,7 @@ private function addRemovedIds(): string
 
         return <<<EOF
 
-    public function getRemovedIds()
+    public function getRemovedIds(): array
     {
         return {$code};
     }
@@ -1363,7 +1364,7 @@ public function getParameter($name)
         return $this->parameters[$name];
     }
 
-    public function hasParameter($name)
+    public function hasParameter($name): bool
     {
         $name = (string) $name;
         if (isset($this->buildParameters[$name])) {
@@ -1373,12 +1374,12 @@ public function hasParameter($name)
         return isset($this->parameters[$name]) || isset($this->loadedDynamicParameters[$name]) || array_key_exists($name, $this->parameters);
     }
 
-    public function setParameter($name, $value)
+    public function setParameter($name, $value): void
     {
         throw new LogicException('Impossible to call set() on a frozen ParameterBag.');
     }
 
-    public function getParameterBag()
+    public function getParameterBag(): ParameterBagInterface
     {
         if (null === $this->parameterBag) {
             $parameters = $this->parameters;
@@ -1421,26 +1422,12 @@ public function getParameterBag()
     private \$loadedDynamicParameters = {$loadedDynamicParameters};
     private \$dynamicParameters = [];
 
-    /*{$this->docStar}
-     * Computes a dynamic parameter.
-     *
-     * @param string \$name The name of the dynamic parameter to load
-     *
-     * @return mixed The value of the dynamic parameter
-     *
-     * @throws InvalidArgumentException When the dynamic parameter does not exist
-     */
-    private function getDynamicParameter(\$name)
+    private function getDynamicParameter(string \$name)
     {
 {$getDynamicParameter}
     }
 
-    /*{$this->docStar}
-     * Gets the default parameters.
-     *
-     * @return array An array of the default parameters
-     */
-    protected function getDefaultParameters()
+    protected function getDefaultParameters(): array
     {
         return $parameters;
     }
diff --git a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/container_alias_deprecation.php b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/container_alias_deprecation.php
index cd77753e7bec..5b415ef0f379 100644
--- a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/container_alias_deprecation.php
+++ b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/container_alias_deprecation.php
@@ -7,12 +7,13 @@
 use Symfony\Component\DependencyInjection\Exception\LogicException;
 use Symfony\Component\DependencyInjection\Exception\RuntimeException;
 use Symfony\Component\DependencyInjection\ParameterBag\FrozenParameterBag;
+use Symfony\Component\DependencyInjection\ParameterBag\ParameterBagInterface;
 
 /**
  * This class has been auto-generated
  * by the Symfony Dependency Injection Component.
  *
- * @final since Symfony 3.3
+ * @final
  */
 class Symfony_DI_PhpDumper_Test_Aliases_Deprecation extends Container
 {
@@ -31,17 +32,17 @@ public function __construct()
         ];
     }
 
-    public function compile()
+    public function compile(): void
     {
         throw new LogicException('You cannot compile a dumped container that was already compiled.');
     }
 
-    public function isCompiled()
+    public function isCompiled(): bool
     {
         return true;
     }
 
-    public function getRemovedIds()
+    public function getRemovedIds(): array
     {
         return [
             'Psr\\Container\\ContainerInterface' => true,
diff --git a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/custom_container_class_constructor_without_arguments.php b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/custom_container_class_constructor_without_arguments.php
index a5ea8d401581..0066ebcac519 100644
--- a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/custom_container_class_constructor_without_arguments.php
+++ b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/custom_container_class_constructor_without_arguments.php
@@ -9,12 +9,13 @@
 use Symfony\Component\DependencyInjection\Exception\LogicException;
 use Symfony\Component\DependencyInjection\Exception\RuntimeException;
 use Symfony\Component\DependencyInjection\ParameterBag\FrozenParameterBag;
+use Symfony\Component\DependencyInjection\ParameterBag\ParameterBagInterface;
 
 /**
  * This class has been auto-generated
  * by the Symfony Dependency Injection Component.
  *
- * @final since Symfony 3.3
+ * @final
  */
 class ProjectServiceContainer extends \Symfony\Component\DependencyInjection\Tests\Fixtures\Container\ConstructorWithoutArgumentsContainer
 {
@@ -31,17 +32,17 @@ public function __construct()
         $this->aliases = [];
     }
 
-    public function compile()
+    public function compile(): void
     {
         throw new LogicException('You cannot compile a dumped container that was already compiled.');
     }
 
-    public function isCompiled()
+    public function isCompiled(): bool
     {
         return true;
     }
 
-    public function getRemovedIds()
+    public function getRemovedIds(): array
     {
         return [
             'Psr\\Container\\ContainerInterface' => true,
diff --git a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/custom_container_class_with_mandatory_constructor_arguments.php b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/custom_container_class_with_mandatory_constructor_arguments.php
index 371c9e353c7a..e065fce00852 100644
--- a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/custom_container_class_with_mandatory_constructor_arguments.php
+++ b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/custom_container_class_with_mandatory_constructor_arguments.php
@@ -9,12 +9,13 @@
 use Symfony\Component\DependencyInjection\Exception\LogicException;
 use Symfony\Component\DependencyInjection\Exception\RuntimeException;
 use Symfony\Component\DependencyInjection\ParameterBag\FrozenParameterBag;
+use Symfony\Component\DependencyInjection\ParameterBag\ParameterBagInterface;
 
 /**
  * This class has been auto-generated
  * by the Symfony Dependency Injection Component.
  *
- * @final since Symfony 3.3
+ * @final
  */
 class ProjectServiceContainer extends \Symfony\Component\DependencyInjection\Tests\Fixtures\Container\ConstructorWithMandatoryArgumentsContainer
 {
@@ -28,17 +29,17 @@ public function __construct()
         $this->aliases = [];
     }
 
-    public function compile()
+    public function compile(): void
     {
         throw new LogicException('You cannot compile a dumped container that was already compiled.');
     }
 
-    public function isCompiled()
+    public function isCompiled(): bool
     {
         return true;
     }
 
-    public function getRemovedIds()
+    public function getRemovedIds(): array
     {
         return [
             'Psr\\Container\\ContainerInterface' => true,
diff --git a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/custom_container_class_with_optional_constructor_arguments.php b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/custom_container_class_with_optional_constructor_arguments.php
index c10c8a91830c..c3fe6abea157 100644
--- a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/custom_container_class_with_optional_constructor_arguments.php
+++ b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/custom_container_class_with_optional_constructor_arguments.php
@@ -9,12 +9,13 @@
 use Symfony\Component\DependencyInjection\Exception\LogicException;
 use Symfony\Component\DependencyInjection\Exception\RuntimeException;
 use Symfony\Component\DependencyInjection\ParameterBag\FrozenParameterBag;
+use Symfony\Component\DependencyInjection\ParameterBag\ParameterBagInterface;
 
 /**
  * This class has been auto-generated
  * by the Symfony Dependency Injection Component.
  *
- * @final since Symfony 3.3
+ * @final
  */
 class ProjectServiceContainer extends \Symfony\Component\DependencyInjection\Tests\Fixtures\Container\ConstructorWithOptionalArgumentsContainer
 {
@@ -31,17 +32,17 @@ public function __construct()
         $this->aliases = [];
     }
 
-    public function compile()
+    public function compile(): void
     {
         throw new LogicException('You cannot compile a dumped container that was already compiled.');
     }
 
-    public function isCompiled()
+    public function isCompiled(): bool
     {
         return true;
     }
 
-    public function getRemovedIds()
+    public function getRemovedIds(): array
     {
         return [
             'Psr\\Container\\ContainerInterface' => true,
diff --git a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/custom_container_class_without_constructor.php b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/custom_container_class_without_constructor.php
index a397e9b2792f..1c007a5f1c5e 100644
--- a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/custom_container_class_without_constructor.php
+++ b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/custom_container_class_without_constructor.php
@@ -9,12 +9,13 @@
 use Symfony\Component\DependencyInjection\Exception\LogicException;
 use Symfony\Component\DependencyInjection\Exception\RuntimeException;
 use Symfony\Component\DependencyInjection\ParameterBag\FrozenParameterBag;
+use Symfony\Component\DependencyInjection\ParameterBag\ParameterBagInterface;
 
 /**
  * This class has been auto-generated
  * by the Symfony Dependency Injection Component.
  *
- * @final since Symfony 3.3
+ * @final
  */
 class ProjectServiceContainer extends \Symfony\Component\DependencyInjection\Tests\Fixtures\Container\NoConstructorContainer
 {
@@ -28,17 +29,17 @@ public function __construct()
         $this->aliases = [];
     }
 
-    public function compile()
+    public function compile(): void
     {
         throw new LogicException('You cannot compile a dumped container that was already compiled.');
     }
 
-    public function isCompiled()
+    public function isCompiled(): bool
     {
         return true;
     }
 
-    public function getRemovedIds()
+    public function getRemovedIds(): array
     {
         return [
             'Psr\\Container\\ContainerInterface' => true,
diff --git a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services1-1.php b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services1-1.php
index e66edba4a64d..a42d7785185e 100644
--- a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services1-1.php
+++ b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services1-1.php
@@ -9,12 +9,13 @@
 use Symfony\Component\DependencyInjection\Exception\LogicException;
 use Symfony\Component\DependencyInjection\Exception\RuntimeException;
 use Symfony\Component\DependencyInjection\ParameterBag\FrozenParameterBag;
+use Symfony\Component\DependencyInjection\ParameterBag\ParameterBagInterface;
 
 /**
  * This class has been auto-generated
  * by the Symfony Dependency Injection Component.
  *
- * @final since Symfony 3.3
+ * @final
  */
 class Container extends \Symfony\Component\DependencyInjection\Dump\AbstractContainer
 {
@@ -28,17 +29,17 @@ public function __construct()
         $this->aliases = [];
     }
 
-    public function compile()
+    public function compile(): void
     {
         throw new LogicException('You cannot compile a dumped container that was already compiled.');
     }
 
-    public function isCompiled()
+    public function isCompiled(): bool
     {
         return true;
     }
 
-    public function getRemovedIds()
+    public function getRemovedIds(): array
     {
         return [
             'Psr\\Container\\ContainerInterface' => true,
diff --git a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services1.php b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services1.php
index 831aefb5cae5..af24b8cf4412 100644
--- a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services1.php
+++ b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services1.php
@@ -7,12 +7,13 @@
 use Symfony\Component\DependencyInjection\Exception\LogicException;
 use Symfony\Component\DependencyInjection\Exception\RuntimeException;
 use Symfony\Component\DependencyInjection\ParameterBag\FrozenParameterBag;
+use Symfony\Component\DependencyInjection\ParameterBag\ParameterBagInterface;
 
 /**
  * This class has been auto-generated
  * by the Symfony Dependency Injection Component.
  *
- * @final since Symfony 3.3
+ * @final
  */
 class ProjectServiceContainer extends Container
 {
@@ -26,17 +27,17 @@ public function __construct()
         $this->aliases = [];
     }
 
-    public function compile()
+    public function compile(): void
     {
         throw new LogicException('You cannot compile a dumped container that was already compiled.');
     }
 
-    public function isCompiled()
+    public function isCompiled(): bool
     {
         return true;
     }
 
-    public function getRemovedIds()
+    public function getRemovedIds(): array
     {
         return [
             'Psr\\Container\\ContainerInterface' => true,
diff --git a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services10.php b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services10.php
index 081fd05102e2..9dbeb0eae1ee 100644
--- a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services10.php
+++ b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services10.php
@@ -7,12 +7,13 @@
 use Symfony\Component\DependencyInjection\Exception\LogicException;
 use Symfony\Component\DependencyInjection\Exception\RuntimeException;
 use Symfony\Component\DependencyInjection\ParameterBag\FrozenParameterBag;
+use Symfony\Component\DependencyInjection\ParameterBag\ParameterBagInterface;
 
 /**
  * This class has been auto-generated
  * by the Symfony Dependency Injection Component.
  *
- * @final since Symfony 3.3
+ * @final
  */
 class ProjectServiceContainer extends Container
 {
@@ -31,17 +32,17 @@ public function __construct()
         $this->aliases = [];
     }
 
-    public function compile()
+    public function compile(): void
     {
         throw new LogicException('You cannot compile a dumped container that was already compiled.');
     }
 
-    public function isCompiled()
+    public function isCompiled(): bool
     {
         return true;
     }
 
-    public function getRemovedIds()
+    public function getRemovedIds(): array
     {
         return [
             'Psr\\Container\\ContainerInterface' => true,
@@ -73,19 +74,19 @@ public function getParameter($name)
         return $this->parameters[$name];
     }
 
-    public function hasParameter($name)
+    public function hasParameter($name): bool
     {
         $name = (string) $name;
 
         return isset($this->parameters[$name]) || isset($this->loadedDynamicParameters[$name]) || array_key_exists($name, $this->parameters);
     }
 
-    public function setParameter($name, $value)
+    public function setParameter($name, $value): void
     {
         throw new LogicException('Impossible to call set() on a frozen ParameterBag.');
     }
 
-    public function getParameterBag()
+    public function getParameterBag(): ParameterBagInterface
     {
         if (null === $this->parameterBag) {
             $parameters = $this->parameters;
@@ -101,26 +102,12 @@ public function getParameterBag()
     private $loadedDynamicParameters = [];
     private $dynamicParameters = [];
 
-    /**
-     * Computes a dynamic parameter.
-     *
-     * @param string $name The name of the dynamic parameter to load
-     *
-     * @return mixed The value of the dynamic parameter
-     *
-     * @throws InvalidArgumentException When the dynamic parameter does not exist
-     */
-    private function getDynamicParameter($name)
+    private function getDynamicParameter(string $name)
     {
         throw new InvalidArgumentException(sprintf('The dynamic parameter "%s" must be defined.', $name));
     }
 
-    /**
-     * Gets the default parameters.
-     *
-     * @return array An array of the default parameters
-     */
-    protected function getDefaultParameters()
+    protected function getDefaultParameters(): array
     {
         return [
             'empty_value' => '',
diff --git a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services12.php b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services12.php
index 978bd775cff4..02f2469abc56 100644
--- a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services12.php
+++ b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services12.php
@@ -7,12 +7,13 @@
 use Symfony\Component\DependencyInjection\Exception\LogicException;
 use Symfony\Component\DependencyInjection\Exception\RuntimeException;
 use Symfony\Component\DependencyInjection\ParameterBag\FrozenParameterBag;
+use Symfony\Component\DependencyInjection\ParameterBag\ParameterBagInterface;
 
 /**
  * This class has been auto-generated
  * by the Symfony Dependency Injection Component.
  *
- * @final since Symfony 3.3
+ * @final
  */
 class ProjectServiceContainer extends Container
 {
@@ -35,17 +36,17 @@ public function __construct()
         $this->aliases = [];
     }
 
-    public function compile()
+    public function compile(): void
     {
         throw new LogicException('You cannot compile a dumped container that was already compiled.');
     }
 
-    public function isCompiled()
+    public function isCompiled(): bool
     {
         return true;
     }
 
-    public function getRemovedIds()
+    public function getRemovedIds(): array
     {
         return [
             'Psr\\Container\\ContainerInterface' => true,
@@ -77,19 +78,19 @@ public function getParameter($name)
         return $this->parameters[$name];
     }
 
-    public function hasParameter($name)
+    public function hasParameter($name): bool
     {
         $name = (string) $name;
 
         return isset($this->parameters[$name]) || isset($this->loadedDynamicParameters[$name]) || array_key_exists($name, $this->parameters);
     }
 
-    public function setParameter($name, $value)
+    public function setParameter($name, $value): void
     {
         throw new LogicException('Impossible to call set() on a frozen ParameterBag.');
     }
 
-    public function getParameterBag()
+    public function getParameterBag(): ParameterBagInterface
     {
         if (null === $this->parameterBag) {
             $parameters = $this->parameters;
@@ -108,16 +109,7 @@ public function getParameterBag()
     ];
     private $dynamicParameters = [];
 
-    /**
-     * Computes a dynamic parameter.
-     *
-     * @param string $name The name of the dynamic parameter to load
-     *
-     * @return mixed The value of the dynamic parameter
-     *
-     * @throws InvalidArgumentException When the dynamic parameter does not exist
-     */
-    private function getDynamicParameter($name)
+    private function getDynamicParameter(string $name)
     {
         switch ($name) {
             case 'foo': $value = ('wiz'.$this->targetDirs[1]); break;
@@ -129,12 +121,7 @@ private function getDynamicParameter($name)
         return $this->dynamicParameters[$name] = $value;
     }
 
-    /**
-     * Gets the default parameters.
-     *
-     * @return array An array of the default parameters
-     */
-    protected function getDefaultParameters()
+    protected function getDefaultParameters(): array
     {
         return [
             'bar' => __DIR__,
diff --git a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services13.php b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services13.php
index 4cbb648a7880..8e62b81ab28b 100644
--- a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services13.php
+++ b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services13.php
@@ -7,12 +7,13 @@
 use Symfony\Component\DependencyInjection\Exception\LogicException;
 use Symfony\Component\DependencyInjection\Exception\RuntimeException;
 use Symfony\Component\DependencyInjection\ParameterBag\FrozenParameterBag;
+use Symfony\Component\DependencyInjection\ParameterBag\ParameterBagInterface;
 
 /**
  * This class has been auto-generated
  * by the Symfony Dependency Injection Component.
  *
- * @final since Symfony 3.3
+ * @final
  */
 class ProjectServiceContainer extends Container
 {
@@ -29,17 +30,17 @@ public function __construct()
         $this->aliases = [];
     }
 
-    public function compile()
+    public function compile(): void
     {
         throw new LogicException('You cannot compile a dumped container that was already compiled.');
     }
 
-    public function isCompiled()
+    public function isCompiled(): bool
     {
         return true;
     }
 
-    public function getRemovedIds()
+    public function getRemovedIds(): array
     {
         return [
             'Psr\\Container\\ContainerInterface' => true,
diff --git a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services19.php b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services19.php
index a0a29ba8b105..d5482b1ddeb4 100644
--- a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services19.php
+++ b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services19.php
@@ -7,12 +7,13 @@
 use Symfony\Component\DependencyInjection\Exception\LogicException;
 use Symfony\Component\DependencyInjection\Exception\RuntimeException;
 use Symfony\Component\DependencyInjection\ParameterBag\FrozenParameterBag;
+use Symfony\Component\DependencyInjection\ParameterBag\ParameterBagInterface;
 
 /**
  * This class has been auto-generated
  * by the Symfony Dependency Injection Component.
  *
- * @final since Symfony 3.3
+ * @final
  */
 class ProjectServiceContainer extends Container
 {
@@ -32,17 +33,17 @@ public function __construct()
         $this->aliases = [];
     }
 
-    public function compile()
+    public function compile(): void
     {
         throw new LogicException('You cannot compile a dumped container that was already compiled.');
     }
 
-    public function isCompiled()
+    public function isCompiled(): bool
     {
         return true;
     }
 
-    public function getRemovedIds()
+    public function getRemovedIds(): array
     {
         return [
             'Psr\\Container\\ContainerInterface' => true,
@@ -88,19 +89,19 @@ public function getParameter($name)
         return $this->parameters[$name];
     }
 
-    public function hasParameter($name)
+    public function hasParameter($name): bool
     {
         $name = (string) $name;
 
         return isset($this->parameters[$name]) || isset($this->loadedDynamicParameters[$name]) || array_key_exists($name, $this->parameters);
     }
 
-    public function setParameter($name, $value)
+    public function setParameter($name, $value): void
     {
         throw new LogicException('Impossible to call set() on a frozen ParameterBag.');
     }
 
-    public function getParameterBag()
+    public function getParameterBag(): ParameterBagInterface
     {
         if (null === $this->parameterBag) {
             $parameters = $this->parameters;
@@ -118,16 +119,7 @@ public function getParameterBag()
     ];
     private $dynamicParameters = [];
 
-    /**
-     * Computes a dynamic parameter.
-     *
-     * @param string $name The name of the dynamic parameter to load
-     *
-     * @return mixed The value of the dynamic parameter
-     *
-     * @throws InvalidArgumentException When the dynamic parameter does not exist
-     */
-    private function getDynamicParameter($name)
+    private function getDynamicParameter(string $name)
     {
         switch ($name) {
             case 'foo': $value = $this->getEnv('FOO'); break;
@@ -138,12 +130,7 @@ private function getDynamicParameter($name)
         return $this->dynamicParameters[$name] = $value;
     }
 
-    /**
-     * Gets the default parameters.
-     *
-     * @return array An array of the default parameters
-     */
-    protected function getDefaultParameters()
+    protected function getDefaultParameters(): array
     {
         return [
             'env(FOO)' => 'Bar\\FaooClass',
diff --git a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services24.php b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services24.php
index 9909d88589ee..7be80e1856f8 100644
--- a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services24.php
+++ b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services24.php
@@ -7,12 +7,13 @@
 use Symfony\Component\DependencyInjection\Exception\LogicException;
 use Symfony\Component\DependencyInjection\Exception\RuntimeException;
 use Symfony\Component\DependencyInjection\ParameterBag\FrozenParameterBag;
+use Symfony\Component\DependencyInjection\ParameterBag\ParameterBagInterface;
 
 /**
  * This class has been auto-generated
  * by the Symfony Dependency Injection Component.
  *
- * @final since Symfony 3.3
+ * @final
  */
 class ProjectServiceContainer extends Container
 {
@@ -29,17 +30,17 @@ public function __construct()
         $this->aliases = [];
     }
 
-    public function compile()
+    public function compile(): void
     {
         throw new LogicException('You cannot compile a dumped container that was already compiled.');
     }
 
-    public function isCompiled()
+    public function isCompiled(): bool
     {
         return true;
     }
 
-    public function getRemovedIds()
+    public function getRemovedIds(): array
     {
         return [
             'Psr\\Container\\ContainerInterface' => true,
diff --git a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services26.php b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services26.php
index 9be6b232b2ec..ccf7e7ddde8a 100644
--- a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services26.php
+++ b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services26.php
@@ -7,12 +7,13 @@
 use Symfony\Component\DependencyInjection\Exception\LogicException;
 use Symfony\Component\DependencyInjection\Exception\RuntimeException;
 use Symfony\Component\DependencyInjection\ParameterBag\FrozenParameterBag;
+use Symfony\Component\DependencyInjection\ParameterBag\ParameterBagInterface;
 
 /**
  * This class has been auto-generated
  * by the Symfony Dependency Injection Component.
  *
- * @final since Symfony 3.3
+ * @final
  */
 class Symfony_DI_PhpDumper_Test_EnvParameters extends Container
 {
@@ -36,17 +37,17 @@ public function __construct()
         $this->aliases = [];
     }
 
-    public function compile()
+    public function compile(): void
     {
         throw new LogicException('You cannot compile a dumped container that was already compiled.');
     }
 
-    public function isCompiled()
+    public function isCompiled(): bool
     {
         return true;
     }
 
-    public function getRemovedIds()
+    public function getRemovedIds(): array
     {
         return [
             'Psr\\Container\\ContainerInterface' => true,
@@ -88,19 +89,19 @@ public function getParameter($name)
         return $this->parameters[$name];
     }
 
-    public function hasParameter($name)
+    public function hasParameter($name): bool
     {
         $name = (string) $name;
 
         return isset($this->parameters[$name]) || isset($this->loadedDynamicParameters[$name]) || array_key_exists($name, $this->parameters);
     }
 
-    public function setParameter($name, $value)
+    public function setParameter($name, $value): void
     {
         throw new LogicException('Impossible to call set() on a frozen ParameterBag.');
     }
 
-    public function getParameterBag()
+    public function getParameterBag(): ParameterBagInterface
     {
         if (null === $this->parameterBag) {
             $parameters = $this->parameters;
@@ -122,16 +123,7 @@ public function getParameterBag()
     ];
     private $dynamicParameters = [];
 
-    /**
-     * Computes a dynamic parameter.
-     *
-     * @param string $name The name of the dynamic parameter to load
-     *
-     * @return mixed The value of the dynamic parameter
-     *
-     * @throws InvalidArgumentException When the dynamic parameter does not exist
-     */
-    private function getDynamicParameter($name)
+    private function getDynamicParameter(string $name)
     {
         switch ($name) {
             case 'bar': $value = $this->getEnv('FOO'); break;
@@ -146,12 +138,7 @@ private function getDynamicParameter($name)
         return $this->dynamicParameters[$name] = $value;
     }
 
-    /**
-     * Gets the default parameters.
-     *
-     * @return array An array of the default parameters
-     */
-    protected function getDefaultParameters()
+    protected function getDefaultParameters(): array
     {
         return [
             'project_dir' => '/foo/bar',
diff --git a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services33.php b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services33.php
index 97d67b78b302..9c30be1b9777 100644
--- a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services33.php
+++ b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services33.php
@@ -7,12 +7,13 @@
 use Symfony\Component\DependencyInjection\Exception\LogicException;
 use Symfony\Component\DependencyInjection\Exception\RuntimeException;
 use Symfony\Component\DependencyInjection\ParameterBag\FrozenParameterBag;
+use Symfony\Component\DependencyInjection\ParameterBag\ParameterBagInterface;
 
 /**
  * This class has been auto-generated
  * by the Symfony Dependency Injection Component.
  *
- * @final since Symfony 3.3
+ * @final
  */
 class ProjectServiceContainer extends Container
 {
@@ -30,17 +31,17 @@ public function __construct()
         $this->aliases = [];
     }
 
-    public function compile()
+    public function compile(): void
     {
         throw new LogicException('You cannot compile a dumped container that was already compiled.');
     }
 
-    public function isCompiled()
+    public function isCompiled(): bool
     {
         return true;
     }
 
-    public function getRemovedIds()
+    public function getRemovedIds(): array
     {
         return [
             'Psr\\Container\\ContainerInterface' => true,
diff --git a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services8.php b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services8.php
index dc3d321ebfe8..93c7ff45145a 100644
--- a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services8.php
+++ b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services8.php
@@ -7,12 +7,13 @@
 use Symfony\Component\DependencyInjection\Exception\LogicException;
 use Symfony\Component\DependencyInjection\Exception\RuntimeException;
 use Symfony\Component\DependencyInjection\ParameterBag\FrozenParameterBag;
+use Symfony\Component\DependencyInjection\ParameterBag\ParameterBagInterface;
 
 /**
  * This class has been auto-generated
  * by the Symfony Dependency Injection Component.
  *
- * @final since Symfony 3.3
+ * @final
  */
 class ProjectServiceContainer extends Container
 {
@@ -28,17 +29,17 @@ public function __construct()
         $this->aliases = [];
     }
 
-    public function compile()
+    public function compile(): void
     {
         throw new LogicException('You cannot compile a dumped container that was already compiled.');
     }
 
-    public function isCompiled()
+    public function isCompiled(): bool
     {
         return true;
     }
 
-    public function getRemovedIds()
+    public function getRemovedIds(): array
     {
         return [
             'Psr\\Container\\ContainerInterface' => true,
@@ -60,19 +61,19 @@ public function getParameter($name)
         return $this->parameters[$name];
     }
 
-    public function hasParameter($name)
+    public function hasParameter($name): bool
     {
         $name = (string) $name;
 
         return isset($this->parameters[$name]) || isset($this->loadedDynamicParameters[$name]) || array_key_exists($name, $this->parameters);
     }
 
-    public function setParameter($name, $value)
+    public function setParameter($name, $value): void
     {
         throw new LogicException('Impossible to call set() on a frozen ParameterBag.');
     }
 
-    public function getParameterBag()
+    public function getParameterBag(): ParameterBagInterface
     {
         if (null === $this->parameterBag) {
             $parameters = $this->parameters;
@@ -88,26 +89,12 @@ public function getParameterBag()
     private $loadedDynamicParameters = [];
     private $dynamicParameters = [];
 
-    /**
-     * Computes a dynamic parameter.
-     *
-     * @param string $name The name of the dynamic parameter to load
-     *
-     * @return mixed The value of the dynamic parameter
-     *
-     * @throws InvalidArgumentException When the dynamic parameter does not exist
-     */
-    private function getDynamicParameter($name)
+    private function getDynamicParameter(string $name)
     {
         throw new InvalidArgumentException(sprintf('The dynamic parameter "%s" must be defined.', $name));
     }
 
-    /**
-     * Gets the default parameters.
-     *
-     * @return array An array of the default parameters
-     */
-    protected function getDefaultParameters()
+    protected function getDefaultParameters(): array
     {
         return [
             'foo' => 'bar',
diff --git a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services9_as_files.txt b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services9_as_files.txt
index 1589c53c59c9..fadd8f2f2850 100644
--- a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services9_as_files.txt
+++ b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services9_as_files.txt
@@ -362,12 +362,13 @@ use Symfony\Component\DependencyInjection\Exception\InvalidArgumentException;
 use Symfony\Component\DependencyInjection\Exception\LogicException;
 use Symfony\Component\DependencyInjection\Exception\RuntimeException;
 use Symfony\Component\DependencyInjection\ParameterBag\FrozenParameterBag;
+use Symfony\Component\DependencyInjection\ParameterBag\ParameterBagInterface;
 
 /**
  * This class has been auto-generated
  * by the Symfony Dependency Injection Component.
  *
- * @final since Symfony 3.3
+ * @final
  */
 class ProjectServiceContainer extends Container
 {
@@ -426,17 +427,17 @@ class ProjectServiceContainer extends Container
         ];
     }
 
-    public function compile()
+    public function compile(): void
     {
         throw new LogicException('You cannot compile a dumped container that was already compiled.');
     }
 
-    public function isCompiled()
+    public function isCompiled(): bool
     {
         return true;
     }
 
-    public function getRemovedIds()
+    public function getRemovedIds(): array
     {
         return require $this->containerDir.\DIRECTORY_SEPARATOR.'removed-ids.php';
     }
@@ -479,7 +480,7 @@ class ProjectServiceContainer extends Container
         return $this->parameters[$name];
     }
 
-    public function hasParameter($name)
+    public function hasParameter($name): bool
     {
         $name = (string) $name;
         if (isset($this->buildParameters[$name])) {
@@ -489,12 +490,12 @@ class ProjectServiceContainer extends Container
         return isset($this->parameters[$name]) || isset($this->loadedDynamicParameters[$name]) || array_key_exists($name, $this->parameters);
     }
 
-    public function setParameter($name, $value)
+    public function setParameter($name, $value): void
     {
         throw new LogicException('Impossible to call set() on a frozen ParameterBag.');
     }
 
-    public function getParameterBag()
+    public function getParameterBag(): ParameterBagInterface
     {
         if (null === $this->parameterBag) {
             $parameters = $this->parameters;
@@ -513,26 +514,12 @@ class ProjectServiceContainer extends Container
     private $loadedDynamicParameters = [];
     private $dynamicParameters = [];
 
-    /**
-     * Computes a dynamic parameter.
-     *
-     * @param string $name The name of the dynamic parameter to load
-     *
-     * @return mixed The value of the dynamic parameter
-     *
-     * @throws InvalidArgumentException When the dynamic parameter does not exist
-     */
-    private function getDynamicParameter($name)
+    private function getDynamicParameter(string $name)
     {
         throw new InvalidArgumentException(sprintf('The dynamic parameter "%s" must be defined.', $name));
     }
 
-    /**
-     * Gets the default parameters.
-     *
-     * @return array An array of the default parameters
-     */
-    protected function getDefaultParameters()
+    protected function getDefaultParameters(): array
     {
         return [
             'baz_class' => 'BazClass',
diff --git a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services9_compiled.php b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services9_compiled.php
index ea405d4895d4..24c9b6f55fc6 100644
--- a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services9_compiled.php
+++ b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services9_compiled.php
@@ -7,12 +7,13 @@
 use Symfony\Component\DependencyInjection\Exception\LogicException;
 use Symfony\Component\DependencyInjection\Exception\RuntimeException;
 use Symfony\Component\DependencyInjection\ParameterBag\FrozenParameterBag;
+use Symfony\Component\DependencyInjection\ParameterBag\ParameterBagInterface;
 
 /**
  * This class has been auto-generated
  * by the Symfony Dependency Injection Component.
  *
- * @final since Symfony 3.3
+ * @final
  */
 class ProjectServiceContainer extends Container
 {
@@ -59,17 +60,17 @@ public function __construct()
         ];
     }
 
-    public function compile()
+    public function compile(): void
     {
         throw new LogicException('You cannot compile a dumped container that was already compiled.');
     }
 
-    public function isCompiled()
+    public function isCompiled(): bool
     {
         return true;
     }
 
-    public function getRemovedIds()
+    public function getRemovedIds(): array
     {
         return [
             'Psr\\Container\\ContainerInterface' => true,
@@ -423,19 +424,19 @@ public function getParameter($name)
         return $this->parameters[$name];
     }
 
-    public function hasParameter($name)
+    public function hasParameter($name): bool
     {
         $name = (string) $name;
 
         return isset($this->parameters[$name]) || isset($this->loadedDynamicParameters[$name]) || array_key_exists($name, $this->parameters);
     }
 
-    public function setParameter($name, $value)
+    public function setParameter($name, $value): void
     {
         throw new LogicException('Impossible to call set() on a frozen ParameterBag.');
     }
 
-    public function getParameterBag()
+    public function getParameterBag(): ParameterBagInterface
     {
         if (null === $this->parameterBag) {
             $parameters = $this->parameters;
@@ -451,26 +452,12 @@ public function getParameterBag()
     private $loadedDynamicParameters = [];
     private $dynamicParameters = [];
 
-    /**
-     * Computes a dynamic parameter.
-     *
-     * @param string $name The name of the dynamic parameter to load
-     *
-     * @return mixed The value of the dynamic parameter
-     *
-     * @throws InvalidArgumentException When the dynamic parameter does not exist
-     */
-    private function getDynamicParameter($name)
+    private function getDynamicParameter(string $name)
     {
         throw new InvalidArgumentException(sprintf('The dynamic parameter "%s" must be defined.', $name));
     }
 
-    /**
-     * Gets the default parameters.
-     *
-     * @return array An array of the default parameters
-     */
-    protected function getDefaultParameters()
+    protected function getDefaultParameters(): array
     {
         return [
             'baz_class' => 'BazClass',
diff --git a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services9_inlined_factories.txt b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services9_inlined_factories.txt
index 04e7de8981e5..73d2a4909395 100644
--- a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services9_inlined_factories.txt
+++ b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services9_inlined_factories.txt
@@ -28,12 +28,13 @@ use Symfony\Component\DependencyInjection\Exception\InvalidArgumentException;
 use Symfony\Component\DependencyInjection\Exception\LogicException;
 use Symfony\Component\DependencyInjection\Exception\RuntimeException;
 use Symfony\Component\DependencyInjection\ParameterBag\FrozenParameterBag;
+use Symfony\Component\DependencyInjection\ParameterBag\ParameterBagInterface;
 
 /**
  * This class has been auto-generated
  * by the Symfony Dependency Injection Component.
  *
- * @final since Symfony 3.3
+ * @final
  */
 class ProjectServiceContainer extends Container
 {
@@ -94,17 +95,17 @@ class ProjectServiceContainer extends Container
         };
     }
 
-    public function compile()
+    public function compile(): void
     {
         throw new LogicException('You cannot compile a dumped container that was already compiled.');
     }
 
-    public function isCompiled()
+    public function isCompiled(): bool
     {
         return true;
     }
 
-    public function getRemovedIds()
+    public function getRemovedIds(): array
     {
         return require $this->containerDir.\DIRECTORY_SEPARATOR.'removed-ids.php';
     }
@@ -477,7 +478,7 @@ class ProjectServiceContainer extends Container
         return $this->parameters[$name];
     }
 
-    public function hasParameter($name)
+    public function hasParameter($name): bool
     {
         $name = (string) $name;
         if (isset($this->buildParameters[$name])) {
@@ -487,12 +488,12 @@ class ProjectServiceContainer extends Container
         return isset($this->parameters[$name]) || isset($this->loadedDynamicParameters[$name]) || array_key_exists($name, $this->parameters);
     }
 
-    public function setParameter($name, $value)
+    public function setParameter($name, $value): void
     {
         throw new LogicException('Impossible to call set() on a frozen ParameterBag.');
     }
 
-    public function getParameterBag()
+    public function getParameterBag(): ParameterBagInterface
     {
         if (null === $this->parameterBag) {
             $parameters = $this->parameters;
@@ -511,26 +512,12 @@ class ProjectServiceContainer extends Container
     private $loadedDynamicParameters = [];
     private $dynamicParameters = [];
 
-    /**
-     * Computes a dynamic parameter.
-     *
-     * @param string $name The name of the dynamic parameter to load
-     *
-     * @return mixed The value of the dynamic parameter
-     *
-     * @throws InvalidArgumentException When the dynamic parameter does not exist
-     */
-    private function getDynamicParameter($name)
+    private function getDynamicParameter(string $name)
     {
         throw new InvalidArgumentException(sprintf('The dynamic parameter "%s" must be defined.', $name));
     }
 
-    /**
-     * Gets the default parameters.
-     *
-     * @return array An array of the default parameters
-     */
-    protected function getDefaultParameters()
+    protected function getDefaultParameters(): array
     {
         return [
             'baz_class' => 'BazClass',
diff --git a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services9_lazy_inlined_factories.txt b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services9_lazy_inlined_factories.txt
index 39388a6a35c3..713de1b8ff49 100644
--- a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services9_lazy_inlined_factories.txt
+++ b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services9_lazy_inlined_factories.txt
@@ -18,12 +18,13 @@ use Symfony\Component\DependencyInjection\Exception\InvalidArgumentException;
 use Symfony\Component\DependencyInjection\Exception\LogicException;
 use Symfony\Component\DependencyInjection\Exception\RuntimeException;
 use Symfony\Component\DependencyInjection\ParameterBag\FrozenParameterBag;
+use Symfony\Component\DependencyInjection\ParameterBag\ParameterBagInterface;
 
 /**
  * This class has been auto-generated
  * by the Symfony Dependency Injection Component.
  *
- * @final since Symfony 3.3
+ * @final
  */
 class ProjectServiceContainer extends Container
 {
@@ -50,17 +51,17 @@ class ProjectServiceContainer extends Container
         $this->aliases = [];
     }
 
-    public function compile()
+    public function compile(): void
     {
         throw new LogicException('You cannot compile a dumped container that was already compiled.');
     }
 
-    public function isCompiled()
+    public function isCompiled(): bool
     {
         return true;
     }
 
-    public function getRemovedIds()
+    public function getRemovedIds(): array
     {
         return require $this->containerDir.\DIRECTORY_SEPARATOR.'removed-ids.php';
     }
@@ -113,7 +114,7 @@ class ProjectServiceContainer extends Container
         return $this->parameters[$name];
     }
 
-    public function hasParameter($name)
+    public function hasParameter($name): bool
     {
         $name = (string) $name;
         if (isset($this->buildParameters[$name])) {
@@ -123,12 +124,12 @@ class ProjectServiceContainer extends Container
         return isset($this->parameters[$name]) || isset($this->loadedDynamicParameters[$name]) || array_key_exists($name, $this->parameters);
     }
 
-    public function setParameter($name, $value)
+    public function setParameter($name, $value): void
     {
         throw new LogicException('Impossible to call set() on a frozen ParameterBag.');
     }
 
-    public function getParameterBag()
+    public function getParameterBag(): ParameterBagInterface
     {
         if (null === $this->parameterBag) {
             $parameters = $this->parameters;
@@ -147,26 +148,12 @@ class ProjectServiceContainer extends Container
     private $loadedDynamicParameters = [];
     private $dynamicParameters = [];
 
-    /**
-     * Computes a dynamic parameter.
-     *
-     * @param string $name The name of the dynamic parameter to load
-     *
-     * @return mixed The value of the dynamic parameter
-     *
-     * @throws InvalidArgumentException When the dynamic parameter does not exist
-     */
-    private function getDynamicParameter($name)
+    private function getDynamicParameter(string $name)
     {
         throw new InvalidArgumentException(sprintf('The dynamic parameter "%s" must be defined.', $name));
     }
 
-    /**
-     * Gets the default parameters.
-     *
-     * @return array An array of the default parameters
-     */
-    protected function getDefaultParameters()
+    protected function getDefaultParameters(): array
     {
         return [
             'container.dumper.inline_factories' => true,
diff --git a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_adawson.php b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_adawson.php
index 43aa60c5ce2f..4c584f4aa434 100644
--- a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_adawson.php
+++ b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_adawson.php
@@ -7,12 +7,13 @@
 use Symfony\Component\DependencyInjection\Exception\LogicException;
 use Symfony\Component\DependencyInjection\Exception\RuntimeException;
 use Symfony\Component\DependencyInjection\ParameterBag\FrozenParameterBag;
+use Symfony\Component\DependencyInjection\ParameterBag\ParameterBagInterface;
 
 /**
  * This class has been auto-generated
  * by the Symfony Dependency Injection Component.
  *
- * @final since Symfony 3.3
+ * @final
  */
 class ProjectServiceContainer extends Container
 {
@@ -30,17 +31,17 @@ public function __construct()
         $this->aliases = [];
     }
 
-    public function compile()
+    public function compile(): void
     {
         throw new LogicException('You cannot compile a dumped container that was already compiled.');
     }
 
-    public function isCompiled()
+    public function isCompiled(): bool
     {
         return true;
     }
 
-    public function getRemovedIds()
+    public function getRemovedIds(): array
     {
         return [
             'App\\Handler1' => true,
diff --git a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_almost_circular_private.php b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_almost_circular_private.php
index 3ca495283e13..ca85686f6e67 100644
--- a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_almost_circular_private.php
+++ b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_almost_circular_private.php
@@ -7,12 +7,13 @@
 use Symfony\Component\DependencyInjection\Exception\LogicException;
 use Symfony\Component\DependencyInjection\Exception\RuntimeException;
 use Symfony\Component\DependencyInjection\ParameterBag\FrozenParameterBag;
+use Symfony\Component\DependencyInjection\ParameterBag\ParameterBagInterface;
 
 /**
  * This class has been auto-generated
  * by the Symfony Dependency Injection Component.
  *
- * @final since Symfony 3.3
+ * @final
  */
 class Symfony_DI_PhpDumper_Test_Almost_Circular_Private extends Container
 {
@@ -46,17 +47,17 @@ public function __construct()
         $this->aliases = [];
     }
 
-    public function compile()
+    public function compile(): void
     {
         throw new LogicException('You cannot compile a dumped container that was already compiled.');
     }
 
-    public function isCompiled()
+    public function isCompiled(): bool
     {
         return true;
     }
 
-    public function getRemovedIds()
+    public function getRemovedIds(): array
     {
         return [
             'Psr\\Container\\ContainerInterface' => true,
diff --git a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_almost_circular_public.php b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_almost_circular_public.php
index 8834fc727ec7..f7eb154f09fd 100644
--- a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_almost_circular_public.php
+++ b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_almost_circular_public.php
@@ -7,12 +7,13 @@
 use Symfony\Component\DependencyInjection\Exception\LogicException;
 use Symfony\Component\DependencyInjection\Exception\RuntimeException;
 use Symfony\Component\DependencyInjection\ParameterBag\FrozenParameterBag;
+use Symfony\Component\DependencyInjection\ParameterBag\ParameterBagInterface;
 
 /**
  * This class has been auto-generated
  * by the Symfony Dependency Injection Component.
  *
- * @final since Symfony 3.3
+ * @final
  */
 class Symfony_DI_PhpDumper_Test_Almost_Circular_Public extends Container
 {
@@ -55,17 +56,17 @@ public function __construct()
         $this->aliases = [];
     }
 
-    public function compile()
+    public function compile(): void
     {
         throw new LogicException('You cannot compile a dumped container that was already compiled.');
     }
 
-    public function isCompiled()
+    public function isCompiled(): bool
     {
         return true;
     }
 
-    public function getRemovedIds()
+    public function getRemovedIds(): array
     {
         return [
             'Psr\\Container\\ContainerInterface' => true,
diff --git a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_array_params.php b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_array_params.php
index 563c3b7ae601..2b6664cf85e0 100644
--- a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_array_params.php
+++ b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_array_params.php
@@ -7,12 +7,13 @@
 use Symfony\Component\DependencyInjection\Exception\LogicException;
 use Symfony\Component\DependencyInjection\Exception\RuntimeException;
 use Symfony\Component\DependencyInjection\ParameterBag\FrozenParameterBag;
+use Symfony\Component\DependencyInjection\ParameterBag\ParameterBagInterface;
 
 /**
  * This class has been auto-generated
  * by the Symfony Dependency Injection Component.
  *
- * @final since Symfony 3.3
+ * @final
  */
 class ProjectServiceContainer extends Container
 {
@@ -35,17 +36,17 @@ public function __construct()
         $this->aliases = [];
     }
 
-    public function compile()
+    public function compile(): void
     {
         throw new LogicException('You cannot compile a dumped container that was already compiled.');
     }
 
-    public function isCompiled()
+    public function isCompiled(): bool
     {
         return true;
     }
 
-    public function getRemovedIds()
+    public function getRemovedIds(): array
     {
         return [
             'Psr\\Container\\ContainerInterface' => true,
@@ -81,19 +82,19 @@ public function getParameter($name)
         return $this->parameters[$name];
     }
 
-    public function hasParameter($name)
+    public function hasParameter($name): bool
     {
         $name = (string) $name;
 
         return isset($this->parameters[$name]) || isset($this->loadedDynamicParameters[$name]) || array_key_exists($name, $this->parameters);
     }
 
-    public function setParameter($name, $value)
+    public function setParameter($name, $value): void
     {
         throw new LogicException('Impossible to call set() on a frozen ParameterBag.');
     }
 
-    public function getParameterBag()
+    public function getParameterBag(): ParameterBagInterface
     {
         if (null === $this->parameterBag) {
             $parameters = $this->parameters;
@@ -111,16 +112,7 @@ public function getParameterBag()
     ];
     private $dynamicParameters = [];
 
-    /**
-     * Computes a dynamic parameter.
-     *
-     * @param string $name The name of the dynamic parameter to load
-     *
-     * @return mixed The value of the dynamic parameter
-     *
-     * @throws InvalidArgumentException When the dynamic parameter does not exist
-     */
-    private function getDynamicParameter($name)
+    private function getDynamicParameter(string $name)
     {
         switch ($name) {
             case 'array_2': $value = [
@@ -133,12 +125,7 @@ private function getDynamicParameter($name)
         return $this->dynamicParameters[$name] = $value;
     }
 
-    /**
-     * Gets the default parameters.
-     *
-     * @return array An array of the default parameters
-     */
-    protected function getDefaultParameters()
+    protected function getDefaultParameters(): array
     {
         return [
             'array_1' => [
diff --git a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_base64_env.php b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_base64_env.php
index 5652844e3764..ca1292a214e6 100644
--- a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_base64_env.php
+++ b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_base64_env.php
@@ -7,12 +7,13 @@
 use Symfony\Component\DependencyInjection\Exception\LogicException;
 use Symfony\Component\DependencyInjection\Exception\RuntimeException;
 use Symfony\Component\DependencyInjection\ParameterBag\FrozenParameterBag;
+use Symfony\Component\DependencyInjection\ParameterBag\ParameterBagInterface;
 
 /**
  * This class has been auto-generated
  * by the Symfony Dependency Injection Component.
  *
- * @final since Symfony 3.3
+ * @final
  */
 class Symfony_DI_PhpDumper_Test_Base64Parameters extends Container
 {
@@ -28,17 +29,17 @@ public function __construct()
         $this->aliases = [];
     }
 
-    public function compile()
+    public function compile(): void
     {
         throw new LogicException('You cannot compile a dumped container that was already compiled.');
     }
 
-    public function isCompiled()
+    public function isCompiled(): bool
     {
         return true;
     }
 
-    public function getRemovedIds()
+    public function getRemovedIds(): array
     {
         return [
             'Psr\\Container\\ContainerInterface' => true,
@@ -60,19 +61,19 @@ public function getParameter($name)
         return $this->parameters[$name];
     }
 
-    public function hasParameter($name)
+    public function hasParameter($name): bool
     {
         $name = (string) $name;
 
         return isset($this->parameters[$name]) || isset($this->loadedDynamicParameters[$name]) || array_key_exists($name, $this->parameters);
     }
 
-    public function setParameter($name, $value)
+    public function setParameter($name, $value): void
     {
         throw new LogicException('Impossible to call set() on a frozen ParameterBag.');
     }
 
-    public function getParameterBag()
+    public function getParameterBag(): ParameterBagInterface
     {
         if (null === $this->parameterBag) {
             $parameters = $this->parameters;
@@ -90,16 +91,7 @@ public function getParameterBag()
     ];
     private $dynamicParameters = [];
 
-    /**
-     * Computes a dynamic parameter.
-     *
-     * @param string $name The name of the dynamic parameter to load
-     *
-     * @return mixed The value of the dynamic parameter
-     *
-     * @throws InvalidArgumentException When the dynamic parameter does not exist
-     */
-    private function getDynamicParameter($name)
+    private function getDynamicParameter(string $name)
     {
         switch ($name) {
             case 'hello': $value = $this->getEnv('base64:foo'); break;
@@ -110,12 +102,7 @@ private function getDynamicParameter($name)
         return $this->dynamicParameters[$name] = $value;
     }
 
-    /**
-     * Gets the default parameters.
-     *
-     * @return array An array of the default parameters
-     */
-    protected function getDefaultParameters()
+    protected function getDefaultParameters(): array
     {
         return [
             'env(foo)' => 'd29ybGQ=',
diff --git a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_csv_env.php b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_csv_env.php
index 22fd21e0752e..cb25eb4f99d6 100644
--- a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_csv_env.php
+++ b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_csv_env.php
@@ -7,12 +7,13 @@
 use Symfony\Component\DependencyInjection\Exception\LogicException;
 use Symfony\Component\DependencyInjection\Exception\RuntimeException;
 use Symfony\Component\DependencyInjection\ParameterBag\FrozenParameterBag;
+use Symfony\Component\DependencyInjection\ParameterBag\ParameterBagInterface;
 
 /**
  * This class has been auto-generated
  * by the Symfony Dependency Injection Component.
  *
- * @final since Symfony 3.3
+ * @final
  */
 class Symfony_DI_PhpDumper_Test_CsvParameters extends Container
 {
@@ -28,17 +29,17 @@ public function __construct()
         $this->aliases = [];
     }
 
-    public function compile()
+    public function compile(): void
     {
         throw new LogicException('You cannot compile a dumped container that was already compiled.');
     }
 
-    public function isCompiled()
+    public function isCompiled(): bool
     {
         return true;
     }
 
-    public function getRemovedIds()
+    public function getRemovedIds(): array
     {
         return [
             'Psr\\Container\\ContainerInterface' => true,
@@ -60,19 +61,19 @@ public function getParameter($name)
         return $this->parameters[$name];
     }
 
-    public function hasParameter($name)
+    public function hasParameter($name): bool
     {
         $name = (string) $name;
 
         return isset($this->parameters[$name]) || isset($this->loadedDynamicParameters[$name]) || array_key_exists($name, $this->parameters);
     }
 
-    public function setParameter($name, $value)
+    public function setParameter($name, $value): void
     {
         throw new LogicException('Impossible to call set() on a frozen ParameterBag.');
     }
 
-    public function getParameterBag()
+    public function getParameterBag(): ParameterBagInterface
     {
         if (null === $this->parameterBag) {
             $parameters = $this->parameters;
@@ -90,16 +91,7 @@ public function getParameterBag()
     ];
     private $dynamicParameters = [];
 
-    /**
-     * Computes a dynamic parameter.
-     *
-     * @param string $name The name of the dynamic parameter to load
-     *
-     * @return mixed The value of the dynamic parameter
-     *
-     * @throws InvalidArgumentException When the dynamic parameter does not exist
-     */
-    private function getDynamicParameter($name)
+    private function getDynamicParameter(string $name)
     {
         switch ($name) {
             case 'hello': $value = $this->getEnv('csv:foo'); break;
@@ -110,12 +102,7 @@ private function getDynamicParameter($name)
         return $this->dynamicParameters[$name] = $value;
     }
 
-    /**
-     * Gets the default parameters.
-     *
-     * @return array An array of the default parameters
-     */
-    protected function getDefaultParameters()
+    protected function getDefaultParameters(): array
     {
         return [
             'env(foo)' => 'foo,bar',
diff --git a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_dedup_lazy_proxy.php b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_dedup_lazy_proxy.php
index 72b08f7bca60..47112f57454f 100644
--- a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_dedup_lazy_proxy.php
+++ b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_dedup_lazy_proxy.php
@@ -7,12 +7,13 @@
 use Symfony\Component\DependencyInjection\Exception\LogicException;
 use Symfony\Component\DependencyInjection\Exception\RuntimeException;
 use Symfony\Component\DependencyInjection\ParameterBag\FrozenParameterBag;
+use Symfony\Component\DependencyInjection\ParameterBag\ParameterBagInterface;
 
 /**
  * This class has been auto-generated
  * by the Symfony Dependency Injection Component.
  *
- * @final since Symfony 3.3
+ * @final
  */
 class ProjectServiceContainer extends Container
 {
@@ -30,17 +31,17 @@ public function __construct()
         $this->aliases = [];
     }
 
-    public function compile()
+    public function compile(): void
     {
         throw new LogicException('You cannot compile a dumped container that was already compiled.');
     }
 
-    public function isCompiled()
+    public function isCompiled(): bool
     {
         return true;
     }
 
-    public function getRemovedIds()
+    public function getRemovedIds(): array
     {
         return [
             'Psr\\Container\\ContainerInterface' => true,
diff --git a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_deep_graph.php b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_deep_graph.php
index 60f683e512b4..fca5c8504f99 100644
--- a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_deep_graph.php
+++ b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_deep_graph.php
@@ -7,12 +7,13 @@
 use Symfony\Component\DependencyInjection\Exception\LogicException;
 use Symfony\Component\DependencyInjection\Exception\RuntimeException;
 use Symfony\Component\DependencyInjection\ParameterBag\FrozenParameterBag;
+use Symfony\Component\DependencyInjection\ParameterBag\ParameterBagInterface;
 
 /**
  * This class has been auto-generated
  * by the Symfony Dependency Injection Component.
  *
- * @final since Symfony 3.3
+ * @final
  */
 class Symfony_DI_PhpDumper_Test_Deep_Graph extends Container
 {
@@ -30,17 +31,17 @@ public function __construct()
         $this->aliases = [];
     }
 
-    public function compile()
+    public function compile(): void
     {
         throw new LogicException('You cannot compile a dumped container that was already compiled.');
     }
 
-    public function isCompiled()
+    public function isCompiled(): bool
     {
         return true;
     }
 
-    public function getRemovedIds()
+    public function getRemovedIds(): array
     {
         return [
             'Psr\\Container\\ContainerInterface' => true,
diff --git a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_default_env.php b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_default_env.php
index f565cf5f86ba..56f50dd22047 100644
--- a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_default_env.php
+++ b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_default_env.php
@@ -7,12 +7,13 @@
 use Symfony\Component\DependencyInjection\Exception\LogicException;
 use Symfony\Component\DependencyInjection\Exception\RuntimeException;
 use Symfony\Component\DependencyInjection\ParameterBag\FrozenParameterBag;
+use Symfony\Component\DependencyInjection\ParameterBag\ParameterBagInterface;
 
 /**
  * This class has been auto-generated
  * by the Symfony Dependency Injection Component.
  *
- * @final since Symfony 3.3
+ * @final
  */
 class Symfony_DI_PhpDumper_Test_DefaultParameters extends Container
 {
@@ -28,17 +29,17 @@ public function __construct()
         $this->aliases = [];
     }
 
-    public function compile()
+    public function compile(): void
     {
         throw new LogicException('You cannot compile a dumped container that was already compiled.');
     }
 
-    public function isCompiled()
+    public function isCompiled(): bool
     {
         return true;
     }
 
-    public function getRemovedIds()
+    public function getRemovedIds(): array
     {
         return [
             'Psr\\Container\\ContainerInterface' => true,
@@ -60,19 +61,19 @@ public function getParameter($name)
         return $this->parameters[$name];
     }
 
-    public function hasParameter($name)
+    public function hasParameter($name): bool
     {
         $name = (string) $name;
 
         return isset($this->parameters[$name]) || isset($this->loadedDynamicParameters[$name]) || array_key_exists($name, $this->parameters);
     }
 
-    public function setParameter($name, $value)
+    public function setParameter($name, $value): void
     {
         throw new LogicException('Impossible to call set() on a frozen ParameterBag.');
     }
 
-    public function getParameterBag()
+    public function getParameterBag(): ParameterBagInterface
     {
         if (null === $this->parameterBag) {
             $parameters = $this->parameters;
@@ -92,16 +93,7 @@ public function getParameterBag()
     ];
     private $dynamicParameters = [];
 
-    /**
-     * Computes a dynamic parameter.
-     *
-     * @param string $name The name of the dynamic parameter to load
-     *
-     * @return mixed The value of the dynamic parameter
-     *
-     * @throws InvalidArgumentException When the dynamic parameter does not exist
-     */
-    private function getDynamicParameter($name)
+    private function getDynamicParameter(string $name)
     {
         switch ($name) {
             case 'fallback_env': $value = $this->getEnv('foobar'); break;
@@ -114,12 +106,7 @@ private function getDynamicParameter($name)
         return $this->dynamicParameters[$name] = $value;
     }
 
-    /**
-     * Gets the default parameters.
-     *
-     * @return array An array of the default parameters
-     */
-    protected function getDefaultParameters()
+    protected function getDefaultParameters(): array
     {
         return [
             'fallback_param' => 'baz',
diff --git a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_env_in_id.php b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_env_in_id.php
index f0cca3ccfe56..c5c5536ebfb6 100644
--- a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_env_in_id.php
+++ b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_env_in_id.php
@@ -7,12 +7,13 @@
 use Symfony\Component\DependencyInjection\Exception\LogicException;
 use Symfony\Component\DependencyInjection\Exception\RuntimeException;
 use Symfony\Component\DependencyInjection\ParameterBag\FrozenParameterBag;
+use Symfony\Component\DependencyInjection\ParameterBag\ParameterBagInterface;
 
 /**
  * This class has been auto-generated
  * by the Symfony Dependency Injection Component.
  *
- * @final since Symfony 3.3
+ * @final
  */
 class ProjectServiceContainer extends Container
 {
@@ -32,17 +33,17 @@ public function __construct()
         $this->aliases = [];
     }
 
-    public function compile()
+    public function compile(): void
     {
         throw new LogicException('You cannot compile a dumped container that was already compiled.');
     }
 
-    public function isCompiled()
+    public function isCompiled(): bool
     {
         return true;
     }
 
-    public function getRemovedIds()
+    public function getRemovedIds(): array
     {
         return [
             'Psr\\Container\\ContainerInterface' => true,
@@ -86,19 +87,19 @@ public function getParameter($name)
         return $this->parameters[$name];
     }
 
-    public function hasParameter($name)
+    public function hasParameter($name): bool
     {
         $name = (string) $name;
 
         return isset($this->parameters[$name]) || isset($this->loadedDynamicParameters[$name]) || array_key_exists($name, $this->parameters);
     }
 
-    public function setParameter($name, $value)
+    public function setParameter($name, $value): void
     {
         throw new LogicException('Impossible to call set() on a frozen ParameterBag.');
     }
 
-    public function getParameterBag()
+    public function getParameterBag(): ParameterBagInterface
     {
         if (null === $this->parameterBag) {
             $parameters = $this->parameters;
@@ -114,26 +115,12 @@ public function getParameterBag()
     private $loadedDynamicParameters = [];
     private $dynamicParameters = [];
 
-    /**
-     * Computes a dynamic parameter.
-     *
-     * @param string $name The name of the dynamic parameter to load
-     *
-     * @return mixed The value of the dynamic parameter
-     *
-     * @throws InvalidArgumentException When the dynamic parameter does not exist
-     */
-    private function getDynamicParameter($name)
+    private function getDynamicParameter(string $name)
     {
         throw new InvalidArgumentException(sprintf('The dynamic parameter "%s" must be defined.', $name));
     }
 
-    /**
-     * Gets the default parameters.
-     *
-     * @return array An array of the default parameters
-     */
-    protected function getDefaultParameters()
+    protected function getDefaultParameters(): array
     {
         return [
             'env(BAR)' => 'bar',
diff --git a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_errored_definition.php b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_errored_definition.php
index 39e2299f4cdf..01ec2e858076 100644
--- a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_errored_definition.php
+++ b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_errored_definition.php
@@ -7,12 +7,13 @@
 use Symfony\Component\DependencyInjection\Exception\LogicException;
 use Symfony\Component\DependencyInjection\Exception\RuntimeException;
 use Symfony\Component\DependencyInjection\ParameterBag\FrozenParameterBag;
+use Symfony\Component\DependencyInjection\ParameterBag\ParameterBagInterface;
 
 /**
  * This class has been auto-generated
  * by the Symfony Dependency Injection Component.
  *
- * @final since Symfony 3.3
+ * @final
  */
 class Symfony_DI_PhpDumper_Errored_Definition extends Container
 {
@@ -59,17 +60,17 @@ public function __construct()
         ];
     }
 
-    public function compile()
+    public function compile(): void
     {
         throw new LogicException('You cannot compile a dumped container that was already compiled.');
     }
 
-    public function isCompiled()
+    public function isCompiled(): bool
     {
         return true;
     }
 
-    public function getRemovedIds()
+    public function getRemovedIds(): array
     {
         return [
             'Psr\\Container\\ContainerInterface' => true,
@@ -423,19 +424,19 @@ public function getParameter($name)
         return $this->parameters[$name];
     }
 
-    public function hasParameter($name)
+    public function hasParameter($name): bool
     {
         $name = (string) $name;
 
         return isset($this->parameters[$name]) || isset($this->loadedDynamicParameters[$name]) || array_key_exists($name, $this->parameters);
     }
 
-    public function setParameter($name, $value)
+    public function setParameter($name, $value): void
     {
         throw new LogicException('Impossible to call set() on a frozen ParameterBag.');
     }
 
-    public function getParameterBag()
+    public function getParameterBag(): ParameterBagInterface
     {
         if (null === $this->parameterBag) {
             $parameters = $this->parameters;
@@ -451,26 +452,12 @@ public function getParameterBag()
     private $loadedDynamicParameters = [];
     private $dynamicParameters = [];
 
-    /**
-     * Computes a dynamic parameter.
-     *
-     * @param string $name The name of the dynamic parameter to load
-     *
-     * @return mixed The value of the dynamic parameter
-     *
-     * @throws InvalidArgumentException When the dynamic parameter does not exist
-     */
-    private function getDynamicParameter($name)
+    private function getDynamicParameter(string $name)
     {
         throw new InvalidArgumentException(sprintf('The dynamic parameter "%s" must be defined.', $name));
     }
 
-    /**
-     * Gets the default parameters.
-     *
-     * @return array An array of the default parameters
-     */
-    protected function getDefaultParameters()
+    protected function getDefaultParameters(): array
     {
         return [
             'baz_class' => 'BazClass',
diff --git a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_inline_requires.php b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_inline_requires.php
index 8947bc37b63b..5d1c62522863 100644
--- a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_inline_requires.php
+++ b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_inline_requires.php
@@ -7,12 +7,13 @@
 use Symfony\Component\DependencyInjection\Exception\LogicException;
 use Symfony\Component\DependencyInjection\Exception\RuntimeException;
 use Symfony\Component\DependencyInjection\ParameterBag\FrozenParameterBag;
+use Symfony\Component\DependencyInjection\ParameterBag\ParameterBagInterface;
 
 /**
  * This class has been auto-generated
  * by the Symfony Dependency Injection Component.
  *
- * @final since Symfony 3.3
+ * @final
  */
 class ProjectServiceContainer extends Container
 {
@@ -44,17 +45,17 @@ public function __construct()
         };
     }
 
-    public function compile()
+    public function compile(): void
     {
         throw new LogicException('You cannot compile a dumped container that was already compiled.');
     }
 
-    public function isCompiled()
+    public function isCompiled(): bool
     {
         return true;
     }
 
-    public function getRemovedIds()
+    public function getRemovedIds(): array
     {
         return [
             'Psr\\Container\\ContainerInterface' => true,
@@ -110,19 +111,19 @@ public function getParameter($name)
         return $this->parameters[$name];
     }
 
-    public function hasParameter($name)
+    public function hasParameter($name): bool
     {
         $name = (string) $name;
 
         return isset($this->parameters[$name]) || isset($this->loadedDynamicParameters[$name]) || array_key_exists($name, $this->parameters);
     }
 
-    public function setParameter($name, $value)
+    public function setParameter($name, $value): void
     {
         throw new LogicException('Impossible to call set() on a frozen ParameterBag.');
     }
 
-    public function getParameterBag()
+    public function getParameterBag(): ParameterBagInterface
     {
         if (null === $this->parameterBag) {
             $parameters = $this->parameters;
@@ -138,26 +139,12 @@ public function getParameterBag()
     private $loadedDynamicParameters = [];
     private $dynamicParameters = [];
 
-    /**
-     * Computes a dynamic parameter.
-     *
-     * @param string $name The name of the dynamic parameter to load
-     *
-     * @return mixed The value of the dynamic parameter
-     *
-     * @throws InvalidArgumentException When the dynamic parameter does not exist
-     */
-    private function getDynamicParameter($name)
+    private function getDynamicParameter(string $name)
     {
         throw new InvalidArgumentException(sprintf('The dynamic parameter "%s" must be defined.', $name));
     }
 
-    /**
-     * Gets the default parameters.
-     *
-     * @return array An array of the default parameters
-     */
-    protected function getDefaultParameters()
+    protected function getDefaultParameters(): array
     {
         return [
             'inline_requires' => true,
diff --git a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_inline_self_ref.php b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_inline_self_ref.php
index 60a39c608aeb..55de46ff1216 100644
--- a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_inline_self_ref.php
+++ b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_inline_self_ref.php
@@ -7,12 +7,13 @@
 use Symfony\Component\DependencyInjection\Exception\LogicException;
 use Symfony\Component\DependencyInjection\Exception\RuntimeException;
 use Symfony\Component\DependencyInjection\ParameterBag\FrozenParameterBag;
+use Symfony\Component\DependencyInjection\ParameterBag\ParameterBagInterface;
 
 /**
  * This class has been auto-generated
  * by the Symfony Dependency Injection Component.
  *
- * @final since Symfony 3.3
+ * @final
  */
 class Symfony_DI_PhpDumper_Test_Inline_Self_Ref extends Container
 {
@@ -29,17 +30,17 @@ public function __construct()
         $this->aliases = [];
     }
 
-    public function compile()
+    public function compile(): void
     {
         throw new LogicException('You cannot compile a dumped container that was already compiled.');
     }
 
-    public function isCompiled()
+    public function isCompiled(): bool
     {
         return true;
     }
 
-    public function getRemovedIds()
+    public function getRemovedIds(): array
     {
         return [
             'Psr\\Container\\ContainerInterface' => true,
diff --git a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_json_env.php b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_json_env.php
index 47f2e73ac7ab..7d8cb9bfc06c 100644
--- a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_json_env.php
+++ b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_json_env.php
@@ -7,12 +7,13 @@
 use Symfony\Component\DependencyInjection\Exception\LogicException;
 use Symfony\Component\DependencyInjection\Exception\RuntimeException;
 use Symfony\Component\DependencyInjection\ParameterBag\FrozenParameterBag;
+use Symfony\Component\DependencyInjection\ParameterBag\ParameterBagInterface;
 
 /**
  * This class has been auto-generated
  * by the Symfony Dependency Injection Component.
  *
- * @final since Symfony 3.3
+ * @final
  */
 class Symfony_DI_PhpDumper_Test_JsonParameters extends Container
 {
@@ -28,17 +29,17 @@ public function __construct()
         $this->aliases = [];
     }
 
-    public function compile()
+    public function compile(): void
     {
         throw new LogicException('You cannot compile a dumped container that was already compiled.');
     }
 
-    public function isCompiled()
+    public function isCompiled(): bool
     {
         return true;
     }
 
-    public function getRemovedIds()
+    public function getRemovedIds(): array
     {
         return [
             'Psr\\Container\\ContainerInterface' => true,
@@ -60,19 +61,19 @@ public function getParameter($name)
         return $this->parameters[$name];
     }
 
-    public function hasParameter($name)
+    public function hasParameter($name): bool
     {
         $name = (string) $name;
 
         return isset($this->parameters[$name]) || isset($this->loadedDynamicParameters[$name]) || array_key_exists($name, $this->parameters);
     }
 
-    public function setParameter($name, $value)
+    public function setParameter($name, $value): void
     {
         throw new LogicException('Impossible to call set() on a frozen ParameterBag.');
     }
 
-    public function getParameterBag()
+    public function getParameterBag(): ParameterBagInterface
     {
         if (null === $this->parameterBag) {
             $parameters = $this->parameters;
@@ -91,16 +92,7 @@ public function getParameterBag()
     ];
     private $dynamicParameters = [];
 
-    /**
-     * Computes a dynamic parameter.
-     *
-     * @param string $name The name of the dynamic parameter to load
-     *
-     * @return mixed The value of the dynamic parameter
-     *
-     * @throws InvalidArgumentException When the dynamic parameter does not exist
-     */
-    private function getDynamicParameter($name)
+    private function getDynamicParameter(string $name)
     {
         switch ($name) {
             case 'hello': $value = $this->getEnv('json:foo'); break;
@@ -112,12 +104,7 @@ private function getDynamicParameter($name)
         return $this->dynamicParameters[$name] = $value;
     }
 
-    /**
-     * Gets the default parameters.
-     *
-     * @return array An array of the default parameters
-     */
-    protected function getDefaultParameters()
+    protected function getDefaultParameters(): array
     {
         return [
             'env(foo)' => '["foo","bar"]',
diff --git a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_locator.php b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_locator.php
index dc120fb118ae..3855cc45dcab 100644
--- a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_locator.php
+++ b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_locator.php
@@ -7,12 +7,13 @@
 use Symfony\Component\DependencyInjection\Exception\LogicException;
 use Symfony\Component\DependencyInjection\Exception\RuntimeException;
 use Symfony\Component\DependencyInjection\ParameterBag\FrozenParameterBag;
+use Symfony\Component\DependencyInjection\ParameterBag\ParameterBagInterface;
 
 /**
  * This class has been auto-generated
  * by the Symfony Dependency Injection Component.
  *
- * @final since Symfony 3.3
+ * @final
  */
 class ProjectServiceContainer extends Container
 {
@@ -36,17 +37,17 @@ public function __construct()
         $this->aliases = [];
     }
 
-    public function compile()
+    public function compile(): void
     {
         throw new LogicException('You cannot compile a dumped container that was already compiled.');
     }
 
-    public function isCompiled()
+    public function isCompiled(): bool
     {
         return true;
     }
 
-    public function getRemovedIds()
+    public function getRemovedIds(): array
     {
         return [
             'Psr\\Container\\ContainerInterface' => true,
diff --git a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_non_shared_lazy.php b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_non_shared_lazy.php
index 8536f6c67406..243596005d42 100644
--- a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_non_shared_lazy.php
+++ b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_non_shared_lazy.php
@@ -7,12 +7,13 @@
 use Symfony\Component\DependencyInjection\Exception\LogicException;
 use Symfony\Component\DependencyInjection\Exception\RuntimeException;
 use Symfony\Component\DependencyInjection\ParameterBag\FrozenParameterBag;
+use Symfony\Component\DependencyInjection\ParameterBag\ParameterBagInterface;
 
 /**
  * This class has been auto-generated
  * by the Symfony Dependency Injection Component.
  *
- * @final since Symfony 3.3
+ * @final
  */
 class ProjectServiceContainer extends Container
 {
@@ -29,17 +30,17 @@ public function __construct()
         $this->aliases = [];
     }
 
-    public function compile()
+    public function compile(): void
     {
         throw new LogicException('You cannot compile a dumped container that was already compiled.');
     }
 
-    public function isCompiled()
+    public function isCompiled(): bool
     {
         return true;
     }
 
-    public function getRemovedIds()
+    public function getRemovedIds(): array
     {
         return [
             'Psr\\Container\\ContainerInterface' => true,
diff --git a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_non_shared_lazy_as_files.txt b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_non_shared_lazy_as_files.txt
index 3eece3ef66aa..8f94683ed92d 100644
--- a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_non_shared_lazy_as_files.txt
+++ b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_non_shared_lazy_as_files.txt
@@ -34,12 +34,13 @@ use Symfony\Component\DependencyInjection\Exception\InvalidArgumentException;
 use Symfony\Component\DependencyInjection\Exception\LogicException;
 use Symfony\Component\DependencyInjection\Exception\RuntimeException;
 use Symfony\Component\DependencyInjection\ParameterBag\FrozenParameterBag;
+use Symfony\Component\DependencyInjection\ParameterBag\ParameterBagInterface;
 
 /**
  * This class has been auto-generated
  * by the Symfony Dependency Injection Component.
  *
- * @final since Symfony 3.3
+ * @final
  */
 class ProjectServiceContainer extends Container
 {
@@ -64,17 +65,17 @@ class ProjectServiceContainer extends Container
         $this->aliases = [];
     }
 
-    public function compile()
+    public function compile(): void
     {
         throw new LogicException('You cannot compile a dumped container that was already compiled.');
     }
 
-    public function isCompiled()
+    public function isCompiled(): bool
     {
         return true;
     }
 
-    public function getRemovedIds()
+    public function getRemovedIds(): array
     {
         return require $this->containerDir.\DIRECTORY_SEPARATOR.'removed-ids.php';
     }
diff --git a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_private_frozen.php b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_private_frozen.php
index 155220112721..6c498821996d 100644
--- a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_private_frozen.php
+++ b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_private_frozen.php
@@ -7,12 +7,13 @@
 use Symfony\Component\DependencyInjection\Exception\LogicException;
 use Symfony\Component\DependencyInjection\Exception\RuntimeException;
 use Symfony\Component\DependencyInjection\ParameterBag\FrozenParameterBag;
+use Symfony\Component\DependencyInjection\ParameterBag\ParameterBagInterface;
 
 /**
  * This class has been auto-generated
  * by the Symfony Dependency Injection Component.
  *
- * @final since Symfony 3.3
+ * @final
  */
 class ProjectServiceContainer extends Container
 {
@@ -30,17 +31,17 @@ public function __construct()
         $this->aliases = [];
     }
 
-    public function compile()
+    public function compile(): void
     {
         throw new LogicException('You cannot compile a dumped container that was already compiled.');
     }
 
-    public function isCompiled()
+    public function isCompiled(): bool
     {
         return true;
     }
 
-    public function getRemovedIds()
+    public function getRemovedIds(): array
     {
         return [
             'Psr\\Container\\ContainerInterface' => true,
diff --git a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_private_in_expression.php b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_private_in_expression.php
index 58b0d5b1926f..f058ae8bdbdf 100644
--- a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_private_in_expression.php
+++ b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_private_in_expression.php
@@ -7,12 +7,13 @@
 use Symfony\Component\DependencyInjection\Exception\LogicException;
 use Symfony\Component\DependencyInjection\Exception\RuntimeException;
 use Symfony\Component\DependencyInjection\ParameterBag\FrozenParameterBag;
+use Symfony\Component\DependencyInjection\ParameterBag\ParameterBagInterface;
 
 /**
  * This class has been auto-generated
  * by the Symfony Dependency Injection Component.
  *
- * @final since Symfony 3.3
+ * @final
  */
 class ProjectServiceContainer extends Container
 {
@@ -29,17 +30,17 @@ public function __construct()
         $this->aliases = [];
     }
 
-    public function compile()
+    public function compile(): void
     {
         throw new LogicException('You cannot compile a dumped container that was already compiled.');
     }
 
-    public function isCompiled()
+    public function isCompiled(): bool
     {
         return true;
     }
 
-    public function getRemovedIds()
+    public function getRemovedIds(): array
     {
         return [
             'Psr\\Container\\ContainerInterface' => true,
diff --git a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_query_string_env.php b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_query_string_env.php
index a357d16a7370..64fef86a844b 100644
--- a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_query_string_env.php
+++ b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_query_string_env.php
@@ -7,12 +7,13 @@
 use Symfony\Component\DependencyInjection\Exception\LogicException;
 use Symfony\Component\DependencyInjection\Exception\RuntimeException;
 use Symfony\Component\DependencyInjection\ParameterBag\FrozenParameterBag;
+use Symfony\Component\DependencyInjection\ParameterBag\ParameterBagInterface;
 
 /**
  * This class has been auto-generated
  * by the Symfony Dependency Injection Component.
  *
- * @final since Symfony 3.3
+ * @final
  */
 class Symfony_DI_PhpDumper_Test_QueryStringParameters extends Container
 {
@@ -28,17 +29,17 @@ public function __construct()
         $this->aliases = [];
     }
 
-    public function compile()
+    public function compile(): void
     {
         throw new LogicException('You cannot compile a dumped container that was already compiled.');
     }
 
-    public function isCompiled()
+    public function isCompiled(): bool
     {
         return true;
     }
 
-    public function getRemovedIds()
+    public function getRemovedIds(): array
     {
         return [
             'Psr\\Container\\ContainerInterface' => true,
@@ -60,19 +61,19 @@ public function getParameter($name)
         return $this->parameters[$name];
     }
 
-    public function hasParameter($name)
+    public function hasParameter($name): bool
     {
         $name = (string) $name;
 
         return isset($this->parameters[$name]) || isset($this->loadedDynamicParameters[$name]) || array_key_exists($name, $this->parameters);
     }
 
-    public function setParameter($name, $value)
+    public function setParameter($name, $value): void
     {
         throw new LogicException('Impossible to call set() on a frozen ParameterBag.');
     }
 
-    public function getParameterBag()
+    public function getParameterBag(): ParameterBagInterface
     {
         if (null === $this->parameterBag) {
             $parameters = $this->parameters;
@@ -90,16 +91,7 @@ public function getParameterBag()
     ];
     private $dynamicParameters = [];
 
-    /**
-     * Computes a dynamic parameter.
-     *
-     * @param string $name The name of the dynamic parameter to load
-     *
-     * @return mixed The value of the dynamic parameter
-     *
-     * @throws InvalidArgumentException When the dynamic parameter does not exist
-     */
-    private function getDynamicParameter($name)
+    private function getDynamicParameter(string $name)
     {
         switch ($name) {
             case 'hello': $value = $this->getEnv('query_string:foo'); break;
@@ -110,12 +102,7 @@ private function getDynamicParameter($name)
         return $this->dynamicParameters[$name] = $value;
     }
 
-    /**
-     * Gets the default parameters.
-     *
-     * @return array An array of the default parameters
-     */
-    protected function getDefaultParameters()
+    protected function getDefaultParameters(): array
     {
         return [
             'env(foo)' => 'foo=bar&baz[]=qux',
diff --git a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_rot13_env.php b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_rot13_env.php
index 7c1a8a7c774c..3dc9a9263f73 100644
--- a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_rot13_env.php
+++ b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_rot13_env.php
@@ -7,12 +7,13 @@
 use Symfony\Component\DependencyInjection\Exception\LogicException;
 use Symfony\Component\DependencyInjection\Exception\RuntimeException;
 use Symfony\Component\DependencyInjection\ParameterBag\FrozenParameterBag;
+use Symfony\Component\DependencyInjection\ParameterBag\ParameterBagInterface;
 
 /**
  * This class has been auto-generated
  * by the Symfony Dependency Injection Component.
  *
- * @final since Symfony 3.3
+ * @final
  */
 class Symfony_DI_PhpDumper_Test_Rot13Parameters extends Container
 {
@@ -34,17 +35,17 @@ public function __construct()
         $this->aliases = [];
     }
 
-    public function compile()
+    public function compile(): void
     {
         throw new LogicException('You cannot compile a dumped container that was already compiled.');
     }
 
-    public function isCompiled()
+    public function isCompiled(): bool
     {
         return true;
     }
 
-    public function getRemovedIds()
+    public function getRemovedIds(): array
     {
         return [
             '.service_locator.GU08LT9' => true,
@@ -91,19 +92,19 @@ public function getParameter($name)
         return $this->parameters[$name];
     }
 
-    public function hasParameter($name)
+    public function hasParameter($name): bool
     {
         $name = (string) $name;
 
         return isset($this->parameters[$name]) || isset($this->loadedDynamicParameters[$name]) || array_key_exists($name, $this->parameters);
     }
 
-    public function setParameter($name, $value)
+    public function setParameter($name, $value): void
     {
         throw new LogicException('Impossible to call set() on a frozen ParameterBag.');
     }
 
-    public function getParameterBag()
+    public function getParameterBag(): ParameterBagInterface
     {
         if (null === $this->parameterBag) {
             $parameters = $this->parameters;
@@ -121,16 +122,7 @@ public function getParameterBag()
     ];
     private $dynamicParameters = [];
 
-    /**
-     * Computes a dynamic parameter.
-     *
-     * @param string $name The name of the dynamic parameter to load
-     *
-     * @return mixed The value of the dynamic parameter
-     *
-     * @throws InvalidArgumentException When the dynamic parameter does not exist
-     */
-    private function getDynamicParameter($name)
+    private function getDynamicParameter(string $name)
     {
         switch ($name) {
             case 'hello': $value = $this->getEnv('rot13:foo'); break;
@@ -141,12 +133,7 @@ private function getDynamicParameter($name)
         return $this->dynamicParameters[$name] = $value;
     }
 
-    /**
-     * Gets the default parameters.
-     *
-     * @return array An array of the default parameters
-     */
-    protected function getDefaultParameters()
+    protected function getDefaultParameters(): array
     {
         return [
             'env(foo)' => 'jbeyq',
diff --git a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_service_locator_argument.php b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_service_locator_argument.php
index 1fbe964dfb19..19617f2cc592 100644
--- a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_service_locator_argument.php
+++ b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_service_locator_argument.php
@@ -7,12 +7,13 @@
 use Symfony\Component\DependencyInjection\Exception\LogicException;
 use Symfony\Component\DependencyInjection\Exception\RuntimeException;
 use Symfony\Component\DependencyInjection\ParameterBag\FrozenParameterBag;
+use Symfony\Component\DependencyInjection\ParameterBag\ParameterBagInterface;
 
 /**
  * This class has been auto-generated
  * by the Symfony Dependency Injection Component.
  *
- * @final since Symfony 3.3
+ * @final
  */
 class Symfony_DI_PhpDumper_Service_Locator_Argument extends Container
 {
@@ -35,17 +36,17 @@ public function __construct()
         $this->aliases = [];
     }
 
-    public function compile()
+    public function compile(): void
     {
         throw new LogicException('You cannot compile a dumped container that was already compiled.');
     }
 
-    public function isCompiled()
+    public function isCompiled(): bool
     {
         return true;
     }
 
-    public function getRemovedIds()
+    public function getRemovedIds(): array
     {
         return [
             '.service_locator.38dy3OH' => true,
diff --git a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_subscriber.php b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_subscriber.php
index b881b676b755..b8126d542728 100644
--- a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_subscriber.php
+++ b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_subscriber.php
@@ -7,12 +7,13 @@
 use Symfony\Component\DependencyInjection\Exception\LogicException;
 use Symfony\Component\DependencyInjection\Exception\RuntimeException;
 use Symfony\Component\DependencyInjection\ParameterBag\FrozenParameterBag;
+use Symfony\Component\DependencyInjection\ParameterBag\ParameterBagInterface;
 
 /**
  * This class has been auto-generated
  * by the Symfony Dependency Injection Component.
  *
- * @final since Symfony 3.3
+ * @final
  */
 class ProjectServiceContainer extends Container
 {
@@ -32,17 +33,17 @@ public function __construct()
         $this->aliases = [];
     }
 
-    public function compile()
+    public function compile(): void
     {
         throw new LogicException('You cannot compile a dumped container that was already compiled.');
     }
 
-    public function isCompiled()
+    public function isCompiled(): bool
     {
         return true;
     }
 
-    public function getRemovedIds()
+    public function getRemovedIds(): array
     {
         return [
             '.service_locator.nZQiwdg' => true,
diff --git a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_tsantos.php b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_tsantos.php
index d301e88ad50b..099a6e0b66c4 100644
--- a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_tsantos.php
+++ b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_tsantos.php
@@ -7,12 +7,13 @@
 use Symfony\Component\DependencyInjection\Exception\LogicException;
 use Symfony\Component\DependencyInjection\Exception\RuntimeException;
 use Symfony\Component\DependencyInjection\ParameterBag\FrozenParameterBag;
+use Symfony\Component\DependencyInjection\ParameterBag\ParameterBagInterface;
 
 /**
  * This class has been auto-generated
  * by the Symfony Dependency Injection Component.
  *
- * @final since Symfony 3.3
+ * @final
  */
 class ProjectServiceContainer extends Container
 {
@@ -30,17 +31,17 @@ public function __construct()
         ];
     }
 
-    public function compile()
+    public function compile(): void
     {
         throw new LogicException('You cannot compile a dumped container that was already compiled.');
     }
 
-    public function isCompiled()
+    public function isCompiled(): bool
     {
         return true;
     }
 
-    public function getRemovedIds()
+    public function getRemovedIds(): array
     {
         return [
             'Psr\\Container\\ContainerInterface' => true,
diff --git a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_uninitialized_ref.php b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_uninitialized_ref.php
index 95fcf89d26d9..5accf7553d3e 100644
--- a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_uninitialized_ref.php
+++ b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_uninitialized_ref.php
@@ -7,12 +7,13 @@
 use Symfony\Component\DependencyInjection\Exception\LogicException;
 use Symfony\Component\DependencyInjection\Exception\RuntimeException;
 use Symfony\Component\DependencyInjection\ParameterBag\FrozenParameterBag;
+use Symfony\Component\DependencyInjection\ParameterBag\ParameterBagInterface;
 
 /**
  * This class has been auto-generated
  * by the Symfony Dependency Injection Component.
  *
- * @final since Symfony 3.3
+ * @final
  */
 class Symfony_DI_PhpDumper_Test_Uninitialized_Reference extends Container
 {
@@ -31,17 +32,17 @@ public function __construct()
         $this->aliases = [];
     }
 
-    public function compile()
+    public function compile(): void
     {
         throw new LogicException('You cannot compile a dumped container that was already compiled.');
     }
 
-    public function isCompiled()
+    public function isCompiled(): bool
     {
         return true;
     }
 
-    public function getRemovedIds()
+    public function getRemovedIds(): array
     {
         return [
             'Psr\\Container\\ContainerInterface' => true,
diff --git a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_unsupported_characters.php b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_unsupported_characters.php
index f6e1a2da5bd2..b1cb22986c29 100644
--- a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_unsupported_characters.php
+++ b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_unsupported_characters.php
@@ -7,12 +7,13 @@
 use Symfony\Component\DependencyInjection\Exception\LogicException;
 use Symfony\Component\DependencyInjection\Exception\RuntimeException;
 use Symfony\Component\DependencyInjection\ParameterBag\FrozenParameterBag;
+use Symfony\Component\DependencyInjection\ParameterBag\ParameterBagInterface;
 
 /**
  * This class has been auto-generated
  * by the Symfony Dependency Injection Component.
  *
- * @final since Symfony 3.3
+ * @final
  */
 class Symfony_DI_PhpDumper_Test_Unsupported_Characters extends Container
 {
@@ -33,17 +34,17 @@ public function __construct()
         $this->aliases = [];
     }
 
-    public function compile()
+    public function compile(): void
     {
         throw new LogicException('You cannot compile a dumped container that was already compiled.');
     }
 
-    public function isCompiled()
+    public function isCompiled(): bool
     {
         return true;
     }
 
-    public function getRemovedIds()
+    public function getRemovedIds(): array
     {
         return [
             'Psr\\Container\\ContainerInterface' => true,
@@ -95,19 +96,19 @@ public function getParameter($name)
         return $this->parameters[$name];
     }
 
-    public function hasParameter($name)
+    public function hasParameter($name): bool
     {
         $name = (string) $name;
 
         return isset($this->parameters[$name]) || isset($this->loadedDynamicParameters[$name]) || array_key_exists($name, $this->parameters);
     }
 
-    public function setParameter($name, $value)
+    public function setParameter($name, $value): void
     {
         throw new LogicException('Impossible to call set() on a frozen ParameterBag.');
     }
 
-    public function getParameterBag()
+    public function getParameterBag(): ParameterBagInterface
     {
         if (null === $this->parameterBag) {
             $parameters = $this->parameters;
@@ -123,26 +124,12 @@ public function getParameterBag()
     private $loadedDynamicParameters = [];
     private $dynamicParameters = [];
 
-    /**
-     * Computes a dynamic parameter.
-     *
-     * @param string $name The name of the dynamic parameter to load
-     *
-     * @return mixed The value of the dynamic parameter
-     *
-     * @throws InvalidArgumentException When the dynamic parameter does not exist
-     */
-    private function getDynamicParameter($name)
+    private function getDynamicParameter(string $name)
     {
         throw new InvalidArgumentException(sprintf('The dynamic parameter "%s" must be defined.', $name));
     }
 
-    /**
-     * Gets the default parameters.
-     *
-     * @return array An array of the default parameters
-     */
-    protected function getDefaultParameters()
+    protected function getDefaultParameters(): array
     {
         return [
             '\'' => 'oh-no',
diff --git a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_url_env.php b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_url_env.php
index 65a31a1962de..abe0e39a34f4 100644
--- a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_url_env.php
+++ b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_url_env.php
@@ -7,12 +7,13 @@
 use Symfony\Component\DependencyInjection\Exception\LogicException;
 use Symfony\Component\DependencyInjection\Exception\RuntimeException;
 use Symfony\Component\DependencyInjection\ParameterBag\FrozenParameterBag;
+use Symfony\Component\DependencyInjection\ParameterBag\ParameterBagInterface;
 
 /**
  * This class has been auto-generated
  * by the Symfony Dependency Injection Component.
  *
- * @final since Symfony 3.3
+ * @final
  */
 class Symfony_DI_PhpDumper_Test_UrlParameters extends Container
 {
@@ -28,17 +29,17 @@ public function __construct()
         $this->aliases = [];
     }
 
-    public function compile()
+    public function compile(): void
     {
         throw new LogicException('You cannot compile a dumped container that was already compiled.');
     }
 
-    public function isCompiled()
+    public function isCompiled(): bool
     {
         return true;
     }
 
-    public function getRemovedIds()
+    public function getRemovedIds(): array
     {
         return [
             'Psr\\Container\\ContainerInterface' => true,
@@ -60,19 +61,19 @@ public function getParameter($name)
         return $this->parameters[$name];
     }
 
-    public function hasParameter($name)
+    public function hasParameter($name): bool
     {
         $name = (string) $name;
 
         return isset($this->parameters[$name]) || isset($this->loadedDynamicParameters[$name]) || array_key_exists($name, $this->parameters);
     }
 
-    public function setParameter($name, $value)
+    public function setParameter($name, $value): void
     {
         throw new LogicException('Impossible to call set() on a frozen ParameterBag.');
     }
 
-    public function getParameterBag()
+    public function getParameterBag(): ParameterBagInterface
     {
         if (null === $this->parameterBag) {
             $parameters = $this->parameters;
@@ -90,16 +91,7 @@ public function getParameterBag()
     ];
     private $dynamicParameters = [];
 
-    /**
-     * Computes a dynamic parameter.
-     *
-     * @param string $name The name of the dynamic parameter to load
-     *
-     * @return mixed The value of the dynamic parameter
-     *
-     * @throws InvalidArgumentException When the dynamic parameter does not exist
-     */
-    private function getDynamicParameter($name)
+    private function getDynamicParameter(string $name)
     {
         switch ($name) {
             case 'hello': $value = $this->getEnv('url:foo'); break;
@@ -110,12 +102,7 @@ private function getDynamicParameter($name)
         return $this->dynamicParameters[$name] = $value;
     }
 
-    /**
-     * Gets the default parameters.
-     *
-     * @return array An array of the default parameters
-     */
-    protected function getDefaultParameters()
+    protected function getDefaultParameters(): array
     {
         return [
             'env(foo)' => 'postgres://user@localhost:5432/database?sslmode=disable',
diff --git a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_wither.php b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_wither.php
index 9e28c238db67..545638d90f79 100644
--- a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_wither.php
+++ b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_wither.php
@@ -7,12 +7,13 @@
 use Symfony\Component\DependencyInjection\Exception\LogicException;
 use Symfony\Component\DependencyInjection\Exception\RuntimeException;
 use Symfony\Component\DependencyInjection\ParameterBag\FrozenParameterBag;
+use Symfony\Component\DependencyInjection\ParameterBag\ParameterBagInterface;
 
 /**
  * This class has been auto-generated
  * by the Symfony Dependency Injection Component.
  *
- * @final since Symfony 3.3
+ * @final
  */
 class Symfony_DI_PhpDumper_Service_Wither extends Container
 {
@@ -29,17 +30,17 @@ public function __construct()
         $this->aliases = [];
     }
 
-    public function compile()
+    public function compile(): void
     {
         throw new LogicException('You cannot compile a dumped container that was already compiled.');
     }
 
-    public function isCompiled()
+    public function isCompiled(): bool
     {
         return true;
     }
 
-    public function getRemovedIds()
+    public function getRemovedIds(): array
     {
         return [
             'Psr\\Container\\ContainerInterface' => true,